Twelve young patients who suffer from an eye disease causing sight loss will have millions of embryo stem cells injected into their eyes, reported Daily Mail, after an American medical company announced it will begin a stem cell research program in Britain in December.

The clinical trials, which have already been conducted in the United States, will begin in the United Kingdom in cooperation with local surgeons. The company behind the trials is Advanced Cell Technology, Inc. (ACT), which got a permission to proceed with its project in Britain on Sept. 22.

Medical specialists at Moorfields Eye Hospital in London will attempt to use retinal cells derived from embryonic stem cells to treat patients with advanced Stargardt disease, a hereditary condition that leads to sight loss. The technique involves injecting the patients;' eyes with cells. The clinical trials aim to test the safety of the treatment.

It’s the first time that the controversial procedure using human stem cells was approved in Europe. The approval came from the Medicines and Healthcare Products Regulatory Agency.

The embryonic stem cell research debate is over religious and ethical grounds, with some people of faith convinced that the research amounts to killing innocent lives. On the other hand, some people cite the moral imperative to alleviate suffering. There are also plenty of believers caught somewhere in between.

Jeff Field, a spokesman for the U.S. Catholic League, told The Christian Post that, as Catholic, the organization believes that embryonic stem cell research is wrong.

"Especially because every person who ever lived began as an embryo, so there's no way to conduct embryonic stem cell research without killing the embryo, therefore it's like taking human life," Field said.

Stem cells are biological cells found in all multi-cellular organisms, which can divide through mitosis and differentiate into diverse specialized cell types and self-renew to produce more stem cells. In a developing embryo, stem cells can differentiate into all the specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues.

In July, ACT surgeons treated the first patients in the company's clinical trials for Stargardt's Macular Dystrophy (SMD) and Dry Age-Related Macular Degeneration (Dry AMD) in the United States, using retinal pigment epithelial (RPE) cells derived from human embryonic stem cells, according to the company’s website.

Wednesday, the Massachusetts-based medical company received the go-ahead to enroll more of U.S. patients into its trials. ACT has received permission to proceed with its research from the Data and Safety Monitoring Board (DSMB), an independent group of experts who monitor patient safety and treatment efficacy data in clinical trials.

Stargardt’s Macular Dystrophy affects an estimated 80,000 to 100,000 patients in the U.S. and Europe, and causes progressive vision loss, usually starting in people between the ages of 10 to 20, according to the ACT website. Eventually, blindness results from photoreceptor loss associated with degeneration in the pigmented layer of the retina, the retinal pigment epithelium.

The first patient to be treated in the U.S. with stem cell-derived RPE cells was a young woman who was already legally blind as a consequence of this disease, according to the ACT press release.